Wire enamel based on amide-imide hydantoin polymers

ABSTRACT

Amide-imide-hydantoin polymers are prepared from trimellitic anhydride, a diisocyanate and reacting the isocyanate terminated amide-imide with a glycine derivative of the formula ##STR1## WHERE R is aromatic, R 1  are the same or different and are hydrogen or alkyl, R 2  is dialkylamino, alkoxy or aroxy and x is an integer from 2 to 4. A portion of the trimellitic anhydride can be replaced by a dicarboxylic acid, a dianhydride or a tribasic acid. The products are soluble in cresol type solvent.

This is a continuation of application Ser. No. 166,594 filed July 27,1971, now abandoned.

The present invention relates to novel amide-imide-hydantoin polymers.The polymers are useful in making wire enamels to coat electricalconductors.

Due to the complex nature of the product, it is not possible to draw acomplete structure of the product. A representative structure is

--H--II--AI--AA--H--AI--H--AI--H--AI--AI--H--AI--AA--H--AI--II--H--

where AI stands for amide-imide, AA stands for amide-amido, H forhydantoin and II for imide-imide units. The two parts of the formula,(1) amide-imide and (2) hydantoin, culminate in a fairly uniform linkagedistribution rather than in having extremely large blocks of amide-imideor hydantoin linkages. For simplicity, the polymer is shown as--AI--AA--H--II--.

The recurring hydantoin units have the formula ##STR2## IN WHICH Arrepresents an aromatic hydrocarbon or substituted aromatic hydrocarbon,e.g., substituted by halogen such as chloro or bromo, nitro, alkoxy,e.g. methoxy or ethoxy, alkyl, e.g., methyl, ethyl or butyl,dialkylamino, e.g., dimethyl amino acyl, e.g., acetyl or propionyl,carbalkoxy e.g., carbo-methoxy or carbo-ethoxy or cyano. The hydrocarbonring can be derived from benzene, naphthalene, anthracene, diphenyl, ora substituted aromatic compound such as triphenylmethane, a diphenylalkane, e.g., diphenylmethane, diphenylethane or diphenyl propane, adiphenyl alkene, e.g., stilbene, diphenyl ether, diphenyl thioether,diphenylsulfone, or a polyphenyl ether, R₁ is hydrogen or alkyl, usuallyhydrogen or alkyl of 1 to 6 carbon atoms, .[.and Y.]. .Iadd.Y is theresidue of the reaction product of trimellitic anhydride and adiisocyanate having the formula OCN-Z-NCO, where Z .Iaddend.is asdefined for Ar or is alkylene of 4 to 10 carbon atoms, oxyalkylene of 4to 10 atoms, or thioalkylene of 4 to 10 carbon atoms.

The polymers of the present invention having at least 5% of the linkagesas recurring hydantoin units are soluble in cresylic type solvents,e.g., meta paracresol, cresylic acid, etc. In general 20 to 60% of thelinkages preferably are present as recurring hydantoin units.

The wire enamels prepared from the polymers of the present inventionhave outstanding Freon blister resistance when used coated on wire,e.g., copper wire, for hermetic systems (Freon is a fluorinatedhydrocarbon, e.g., monochlorodifluoromethane, Freon 22). Additionally,the wire enamels exhibit a general higher than average cut-throughvalue, and higher G.E. abrasion scrape resistance than other cresylicacid soluble wire enamels.

The preferred procedure for forming the amide-imide-hydantoin polymersof the present invention is to react a diisocyanate with trimelliticanhydride, usually at 100% solids (i.e. in the absence of a solvent)(see also Sumitomo British Pat. 1,220,590). This permits the formationof an isocyanate terminated amide-imide prepolymer with no interferencefrom the cresol type solvent. The amide-imide polymer has 20-80% amidegroups and 80-20% imide groups, preferably 30-70% amide groups and70-30% imide groups.

As the diisocyanate there can be used aromatic, aliphatic andcycloaliphatic diisocyanates such as 4,4'-methylene diphenyldiisocyanate, 2,4-toluene diisocyanate, isophorone diisocyanate,2,6-toluene diisocyanate, ethyl benzene diisocyanate, tetramethylenediisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate,octamethylene diisocyanate, decamethylene diisocyanate, diisopropylbenzene diisocyanate, tri-isopropyl benzene diisocyanate,2-chloro-p-phenylene diisocyanate, naphthalene diisocyanate,glycol-di-p-isocyanato phenyl ester, 4,4'-diisocyanato-diphenyl ether,1,2-bis-p-isocyanato-phenylethane, 4,4'-diisocyanato-stilbene,4,4'-diphenyl sulfone diisocyanate, 3,5,6-trichlorotolylenediisocyanate, xylylene diisocyanate, propyl benzene diisocyanate,m-phenylene diisocyanate, p-phenylene diisocyanate, dodecamethylenediisocyanate, tetrachloro-m-phenylene diisocyanate, 4,4'-bis-o-tolylenediisocyanate, 4,4'-methylene-di-o-tolylisocyanate,4-methoxy-1,3-phenylene diisocyanate, 4-chloro-1,3-phenylenediisocyanate, 4-isopropyl-1,3-phenylene diisocyanate,2,4'-diisocyanatodiphenyl ether, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, mesitylene diisocyanate, durylene diisocyanate.

After the isocyanate terminated amide-imide prepolymer is made, it isdissolved in a solvent, usually a cresylic solvent, e.g., p-cresol,o-cresol, m-cresol, cresylic acid or even in phenol with or without ahydrocarbon diluent, and is reacted with a glycine ester of the formula##STR3## where Ar is as defined above, R₁ is as defined above (the R₁groups can be the same or different), R₂ is dialkylamino, alkoxy oraryloxy, and x is an integer from 2 to 4. Thus, there can be usedglycine derivatives disclosed in Merten, British Pat. 1,106,915, Mar.20, 1968, e.g., methylene bis(N-phenyl glycine ethyl ester), methylenebis(N-phenyl glycine methyl ester), methylene bis(N-phenyl glycinepropyl ester), methylene bis(N-phenyl glycine isopropyl ester),methylene bis (N-phenyl glycine butyl ester), methylene bis(N-phenylglycine sec. butyl ester), methylene bis(N-phenyl glycine hexyl ester),methylene bis(N-phenyl glycine cyclohexyl ester), methylene bis(N-phenylglycine isooctyl ester), methylene bis(N-phenyl glycine), methylenebis(N-phenyl N',N'-dimethyl glycinamide), methylene bis(N-phenyl-N',N'-dibutyl glycinamide), methylene bis(N-phenyl glycinephenyl ester), methylene bis (N-phenyl glycine p-tolyl ester),oxybis(N-phenyl glycine ethyl ester), oxybis(N-phenyl glycine methylester), thiobis (N-phenyl glycine ethyl ester), thiobis(phenyl glycinebutyl ester), sulfone bis(N-phenyl glycine ethyl ester),oxybis(N-3-chlorophenyl glycine ethyl ester), oxybis(N-2-chlorophenylglycine methyl ester), ethylene bis(N-phenyl glycine ethyl ester),tetramethylene bis(N-phenyl glycine amyl ester), hexamethylenebis(N-phenyl glycine methyl ester), decamethylene bis(N-phenyl glycineethyl ester), diphenyl 4,4'-bis(glycine ethyl ester),stilbene-4,4'-bis(glycine ethyl ester), N,N'-biscarboxymethyl-2,2'-diaminobenzene,N,N'-bis(methoxycarbonyldimethyl-methyl)-4,4'-diaminodiphenyl methane,ethylidene bis (N-phenyl glycine ethyl ester), isopropylidenebis(N-phenyl glycine ethyl ester), butylidene bis(N-phenyl glycinepropyl ester), tridecane 6,6-bis(N-phenyl glycine ethyl ester),N,N'-bis(methoxycarbonyl-dimethyl-methyl) m-phenylene diamine.

In the reaction of the trimellitic anhydride with the isocyanate, aportion of the trimellitic anhydride can be replaced by a dicarboxylicacid or a difunctional anhydride, i.e. a carboxylic dianhydride, in anamount of 0.1 to 50 mole percent based on the moles of trimelliticanhydride. Such dicarboxylic acids and dianhydrides include, forexample, isophthalic acid (15 molar percent preferred), terephthalicacid (preferably not over 20 molar percent and most preferably 8 molarpercent) phenylindane dicarboxylic acid, adipic acid, pimelic acid,4,4'-dicarboxy diphenyl ether, 4,4'-dicarboxy diphenyl sulfone,benzophenone dianhydride, cyclopentane dianhydride and pyromelliticdianhydride. The only dicarboxylic acids which should be excluded arethose which form imides by reaction with amines or isocyanates (e.g.,ortho phthalic acid and glutaric acid).

A small portion of the trimellitic anhydride can be replaced by atrifunctional carboxylic acid to institute branching. Thus there can beused up to about 10 molar percent trimesic acid based on the trimelliticanhydride.

The molar ratio acid and anhydride reactants to methylene bis(N-phenylglycine ethyl ester) or other hydantoin forming material can be from ahigh of 95:5 to a low of 5:95.

In general the range of reactants is as follows:

(1) diisocyanate 0.85 to 1.05 moles (1.00 preferred)

(2) glycine derivative 0.05 to 0.95 mole (0.40 preferred)

(3) trimellitic anhydride .Badd..[. 0.05 or 0.5-0.6.]..Baddend..Iadd.0.95 .Iaddend.to 0.01 mole (0.4-0.5 preferred). .Iadd.A morespecific range is 0.5-0.6 mole. .Iaddend.

(4) dicarboxylic acid 0.0 to 0.3 mole (0.15 preferred)

(5) dianhydride 0.0 to 0.3 mole (0.2 preferred)

(6) tricarboxylic acid 0.0 to 0.05 mole (0.033 preferred)

(7) organometallic content, preferably organic titanates (0.0 to 1.0mole (0.0-0.06 preferred).

The total of (2), (3), (4), (5) and (6) should range from 1.05 to 0.95moles (preferably 1.00), i.e. the equivalents of diisocyanate ordiisocyanate and organic titanate are about equal to the equivalents ofthe other reactants.

The organic titanate can be up to about 15 equivalent percent of thediisocyanate.

The reaction temperature is not critical but usually the hydantoins areformed by reacting at 80°-500° C.

The solvents are preferably of the phenolic type as stated, e.g.,cresylic acid, or individual cresols or mixtures thereof alone or withphenol, xylenol, chlorophenol, etc. When a hydrocarbon diluent ispresent, it can be present in an amount up to 46.5% or more of thesolvent by volume, usually it is 10-25% of the solvent mixture byvolume. Examples of such diluents are xylene, toluene, enamel wirenaphtha, Solvesso 100 (aromatic naphtha boiling range 316°-338° F.),Solvesso 150 (aromatic naphtha 366°-399° F.), N-150 (aromatic naphthenes372°-500° F.).

Unless otherwise indicated, all parts and percentages are by weight.

The wire enamels prepared in the present invention can be applied to anelectrical conductor, e.g. copper, silver, aluminum or stainless steelwire in conventional fashion, e.g., by the "free dip" method or the "dieapplication" procedure, both of which procedures are described in MeyerPat. 3,201,276. Wire speeds of 30 to 50 feet per minute or higher can beused with wire tower temperatures of 250°-800° F., usually with a finaltemperature of above 500° F. The build-up of thepolyamide-imide-hydantoin enamel on the wire can be 0.005 to 0.010 inch,preferably 0.002 to 0.004 inch using No. 18 wire. The wire is passedthrough the enamel one or more times until the desired build-up isobtained. (The build-up is the total increase in diameter over the barewire diameter).

                  EXAMPLE 1                                                       ______________________________________                                                                         G.                                           (1)  4,4'-Methylene Diphenyl Diisocyanate (1.0 m.)                                                             250                                          (2)  Trimellitic Anhydride (0.5 m.)                                                                            96                                                Terephthalic Acid (0.1 m.)  16                                           (3)  Methylene bis(N-phenyl glycine ethyl ester)                                   (0.4 m.)                    148                                          (4)  N-methyl-2-pyrrolidone      40                                           (5)  M.P. Cresol                 246                                               C.P. Phenol                 494                                               Ortho Cresol                146                                          (6)  Cresylic Acid               582                                               Xylene                      120                                               Phenol                      200                                          ______________________________________                                    

(1) was charged to a kettle equipped with an inert atmosphere inlet,agitator, reflux condenser and thermometer. (2) was added slowly whilethe temperature was increased to 330° F. The reaction temperature washeld at 330°-340° F. for 40 minutes. At the end of this period (4) wasadded. The batch began to liberate CO₂ rapidly. 200 g. of (5) was added.At 340° F. (3) was slowly added, until the batch temperature was 390° F.At this point the balance of (5) was added. The temperature dropped to240° F. Heat was applied to a temperature of 380° F. It was held at thistemperature. At this point (6) was added. The batch was cooled andfiltered to provide wire enamel 1 having a final viscosity of X(Gardner-Holdt).

                  EXAMPLE 2                                                       ______________________________________                                                                         G.                                           (1)  4,4' Methylene Diphenyl Diisocyanate (1.0                                     m.)                         250                                               N-Methyl-2-pyrrolidone      20                                           (2)  Trimellitic Anhydride (0.5 m.)                                                                            96                                           (3)  Methylene bis (N-phenyl glycine ethyl ester                                   (0.5 m.)                    185                                          (4)  M.P. Cresol                 246                                               C.P. Phenol                 494                                               Ortho Cresol                146                                          (5)  Cresylic Acid               582                                               Xylene                      420                                          ______________________________________                                    

(1) was added to the same type apparatus described in Example 1. (2) wasadded in the same manner. At 340° F. the batch began to eliminate CO₂ ata rapid rate. It was allowed to increase in temperature to 390° F. whereit was thinned with (4). It was heated back up to 280° F. whereupon (3)was added rapidly. The batch was then heated to 380° F. until 27 gms. ofethanol had been removed. Then (5) was added. The batch was cooled andfiltered to provide wire enamel 2 having a final viscosity at 17.5%solids of Z1⁺ (Gardner-Holdt).

                  EXAMPLE 3                                                       ______________________________________                                                                         G.                                           (1)  4,4' Methylene Diphenyl Diisocyanate (1.0                                     m.)                         250                                          (2)  Trimellitic Anhydride (0.5 m.)                                                                            96                                           (3)  Methylene bis (N-phenyl glycine ethyl ester)                                  (0.5 m.)                    185                                          (4)  M.P. Cresol                 246                                               C.P. Phenol                 494                                               Ortho Cresol                146                                          (5)  4,4' Methylene Diphenyl Diisocyanate                                                                      20                                           (6)  Cresylic Acid               382                                               Xylene                      120                                               C.P. Phenol                 200                                          ______________________________________                                    

(2) was added slowly to (1). The maximum temperature obtained was 340°F. The batch was held at 340° F. for one hour and 15 minutes whereuponhalf of (3) was added, then (4) was added, and the balance of (3) addedafter the temperature was raised from 180° F. to 240° F. The temperaturewas further increased to 380° F. and held. Only 16 ml. of ethanol wereremoved after 2 hours. At 380° F. (5) was added and held at 380° F. foran additional 1 to 2 hours. No additional ethanol was removed. The batchwas filtered and cooled after the addition of (6) to give wire enamel 3having a final viscosity of 20% solids of R (Gardner-Holdt).

                  EXAMPLE 4                                                       ______________________________________                                                                         G.                                           (1)  4,4' Methylene Diphenyl Diisocyanate (1.0                                     m.)                         250                                               N-Methyl-2-pyrrolidone      20                                           (2)  Trimellitic Anhydride       96                                           (3)  Methylene bis (N-phenyl glycine ethyl ester)                                  (0.4 m.)                    148                                          (4)  Cresylic Acid ADF-14        1000                                         (5)  Solvesso 100                400                                          (6)  Cresylic Acid               182                                               Solvesso 100                64                                           ______________________________________                                    

(2) was added to (1) over a half-hour period, the temperature beingaround 250° F. The temperature was raised to 340° F. at which point anexotherm was observed up to 362° F. At 362° F. 200 gms. of (4) wasadded. The temperature was raised to 350° F. and (3) was added slowly.The temperature was raised to 380° F. and after 14 gms. of ethanol hadbeen collected the balance of (4) was added. The temperature was raisedto 390° F. At this point (5) and (6) were added. The batch was cooled,and filtered to give wire enamel 4 having a final viscosity of X⁺(Gardner-Holdt) at 20% solids.

                  EXAMPLE 5                                                       ______________________________________                                                                         G.                                           (1)  4,4' Methylene Diphenyl Diisocyanate (1.0                                     m.)                         250                                               Trimellitic Anhydride (0.6 m.)                                                                            116                                               N-methyl-2-pyrrolidone      30                                           (2)  M.P. Cresol                 200                                          (3)  Methylene bis (N-phenyl glycine ethyl ester)                                  (0.4 m.-2 g.)               146                                          (4)  Cresylic Acid ADF-14        848                                          (5)  Solvesso 100                424                                          (6)  M.P. Cresol                 224                                          ______________________________________                                    

(1) was heated slowly to 340° F., at which point an exotherm occurred to388° F. At this point (2) was added, the temperature fell to 322° F. and(3) was added all at once. While the temperature was being raised (4)was added slowly. At the end of the addition the reaction temperaturewas raised to 380° F. At this point (5) and (6) were added. The batchwas cooled and filtered to give wire enamel 5 having a final viscosityof X-Y (Gardner-Holdt) at 20% solids.

                  EXAMPLE 6                                                       ______________________________________                                                                         G.                                           (1)  4,4' Methylene diphenyl diisocyanate (1 m.)                                                               250                                               Trimellitic anhydride (0.6 m.)                                                                            115                                          (2)  N-methyl-2-pyrrolidone      40                                           (3)  C.P. Phenol                 200                                          (4)  Methylene bis (N-phenyl glycine ethyl ester)                                  (0.4 m.)                    148                                          (5)  C.P. Phenol                 654                                               Ortho Cresol                256                                               M.P. Cresol (meta-para cresol)                                                                            598                                          (6)  4,4' Methylene diphenyl diisocyanate                                                                      15                                           (7)  Xylene                      256                                          ______________________________________                                    

(1) was heated to 410° F. Then the temperature was lowered to 340° F.whereupon (2) was added. The temperature was raised to 360° F. and (3)was added. Immediately after the addition of (3), (4) was added alongwith 250 g. of (5). The temperature was raised to 390° F. whereupon (6)was added and held for one more hour. At the end of this period, thebatch was thinned with the balance of (5) and (7). The wire enamel thusproduced has a final viscosity of X⁻ (Gardner-Holdt) at 17.5% solids.

                  EXAMPLE 7                                                       ______________________________________                                                                         G.                                           (1)  4,4' Methylene Diphenyl                                                       Diisocyanate (1 m.+5 g.)    255                                               Trimellitic Anhydride (0.6 m.)                                                                            109                                               Trimesic Acid (0.033 m.)    7                                            (2)  N-methyl-2-pyrrolidone      40                                           (3)  Cresylic Acid               200                                          (4)  Methylene bis (N-phenyl glycine                                               ethyl ester) (0.4 m.)       148                                          (5)  Cresylic Acid               1173                                         (6)  Solvesso 100                343                                          ______________________________________                                    

(1) was heated slowly to 380° F. The batch was cooled to 350° F. and (2)was added. The temperature was raised to 380° F. and (3) was added. At350° F. (4) was added along with 500 gms. of (5). The batch was heatedto 380° F. At this point an additional 250 gms. of (5) were added. Thetemperature was now raised to 400° F. At this point the balance of (5)was added along with (6). The batch was cooled and filtered to producewire enamel 7 having a final viscosity of Z2 (Gardner-Holdt) at 20%solids.

The resulting wire enamels were applied to No. 18 copper wire and theresults recorded in Table 1.

                                      TABLE 1                                     __________________________________________________________________________                                     Mandrel    (200° C.)                                                                        (600                                                                              GE                           Build                   after                                                                              Cut thru                                                                            Heat      p.s.i.)                                                                           repeated            Example                                                                            Speed                                                                             (mils)                                                                              Appearance        snap ° C.                                                                         shock     Freon                                                                             scrape              __________________________________________________________________________    1    40  2,9-3.0                                                                             Good              2×                                                                           421-400                                                                             50-90-100-100                                                                           OK  69                  2    40  2.8   Very slightly wavy plus med. gr.                                                                2×                                                                           300-400                                                                             0-90-100-100  52                  3    35  3.0   Good, sl. gr.     3×                                                                           420-410                                                                             0-50-90-100   30                  4    35  2.8   Very slightly wavy plus med. gr.                                                                3×                                                                            380-450+                                                                           0-50-70-70                                                                              OK  312                 5    35  2.8   Very slight wave, med. gr.                                                                      3×                                                                           415-405                                                                             0-50-60-80    70                  6    30  2.7   Very slightly wavy plus med. gr.                                                                2×                                                                           399-388                                                                             0-60-80-90    147                 7    40  2.6   "                 2×                                                                           370-382                                                                             20-70-90-90   43                  __________________________________________________________________________

                  EXAMPLE 8                                                       ______________________________________                                                                         G.                                           (1)  4,4' methylene diphenyl                                                       diisocyanate (1.0 m.)       250                                               Trimellitic anhydride (0.5 m.)                                                                            96                                                Benzophenone dianhydride (0.05 m.)                                                                        16                                                Isophthalic acid (0.05 m.)  8                                            (2)  Tributyl amine              5                                            (3)  Cresylic acid               700                                          (4)  Methylene bis (N-phenylglycine                                                ethyl ester) (0.4 m.)       148                                          (5)  Cresylic acid               1079                                              Solvesso 100 (15% of solvent)                                                                             319                                          ______________________________________                                    

(1) was charged into a 3-liter kettle and the temperature was increasedto 370° F. over a period of 70 minutes. At 370° F. (2) was addeddropwise while the batch was held at a minimum temperature of 360° F.for 50 minutes. At the end of this period (3) was added to dissolve thepolymer formed. When all was dissolved (4) was added at 300° F. Thetemperature was raised to 400° F. over a period of 5 hours, then thebatch was thinned with (5). The final viscosity and solids were X 3/4(Gardner-Holdt) at 17% solids.

    __________________________________________________________________________    WIRE RESULTS                                                                  __________________________________________________________________________       Speed            35"/min   40'/min.                                           Appearance       Good      Good                                               Mandrel after snap                                                                             4×  2×                                        .[.Gut.].                                                                        .Iadd.Cut.Iaddend.through                                                                      39-410° C                                                                        302-378° C.                                 Heat shock (200° C.)                                                                    20-60-90-100                                                                            50-90-100-100.                                     Freon resistance (600 p.s.i.)                                                                  OK        OK.                                             .[.OE.].                                                                         .Iadd.GE.Iaddend. repeated scrape                                                              184       126                                             __________________________________________________________________________

                  EXAMPLE 9                                                       ______________________________________                                                                     G.                                               (1)  4,4' methylene diphenyl diisocyanate                                                                  8000                                                  Trimellitic anhydride   3072                                                  Benzophenone dianhydride                                                                              1024                                             (2)  Tributyl amine          160                                              (3)  Cresylic acid           30,400                                           (4)  Methylene bis (N-phenyl glycine                                               ethyl ester)            4736                                             (5)  C.P. Phenol             13,623                                           (6)  Solvesso 100            10,240                                           (7)  Cresylic acid           21,888                                           ______________________________________                                    

(1) was charged into a 15-gallon kettle and heated to 382° F. over aperiod of about 3 hours. At 382° F. (2) was added slowly over a periodof 15 minutes then the batch was held for an additional 15 minutes. Atthe end of this period (3) was added to dissolve the polymer. Whencompletely dissolved the temperature was adjusted to 300° F. and (4) wasadded. The heat was increased to a maximum of 402° F. over a period of 7hours until a 25% check cut in cresylic acid was at N⁺ viscosity with atleast 1000 ml. of ethanol removed. The batch was then thinned with (5),(6) and (7).

    __________________________________________________________________________    WIRE RESULTS                                                                  __________________________________________________________________________    Speed            35'/min    40'/min.                                          Appearance       Good, med. gr.                                                                           Good, med. gr.                                    Mandrel after snap                                                                             3×   2×                                          Cut through      420-21° C.                                                                        319-360° C.                                Heat shock (260° C.)                                                                    20-70-90-100                                                                             40-80-100-100.                                    __________________________________________________________________________

                  EXAMPLE 10                                                      ______________________________________                                                                         G.                                           (1)  4,4'-Methylene diphenyl                                                       diisocyanate (1.0 m.)       250                                               Trimellitic anhydride (0.4 m.)                                                                            77                                                Benzophenone dianhydride (0.2 m.)                                                                         64                                           (2)  Tributyl amine              5                                            (3)  Cresylic acid               700                                          (4)  Methylene bis(N-phenyl glycine                                                ethyl ester) (0.4 m.)       148                                          (5)  Cresylic acid               646                                          (6)  C.P. Phenol                 431                                          (7)  Solvesso 100                323                                          ______________________________________                                    

(1) was charged into a 3 liter kettle and heated with agitation over aperiod of 2 hours to a maximum temperature of 417° F. at which point (2)was slowly added followed by (3). After the polymer was dissolved in (3)and the temperature adjusted to 310° F., (4) was added and heated to408° F. over a period of 10 hours, then it was thinned with (5), (6) and(7).

    ______________________________________                                        WIRE RESULTS                                                                  ______________________________________                                        Speed                40'/min.                                                 Build                2.7 mils.                                                Mandrel after snap   2×                                                 Appearance           Good.                                                    Cut through          385-388° C.                                       Heat shock (260° C.)                                                                        50-90-90-100.                                            GE Repeated Scrape   49.                                                      ______________________________________                                    

                  EXAMPLE 11                                                      ______________________________________                                                                         G.                                           (1)  4,4'-Methylene diphenyl Diisocyanate                                          (0.9 m.)                    225                                               Trimellitic anhydride (0.4 m.)                                                                            77                                                Benzophenone dianhydride (0.2 m.)                                                                         64                                           (2)  Tributyl amine              5                                            (3)  Cresylic acid               1000                                         (4)  Methylene bis(N-phenylglycine ethyl ester)                                    (0.4 m.)                    148                                          (5)  Cresylic acid               475                                          (6)  Ethyl Cellosolve (5% of solvent)                                                                          87                                           (7)  Solvesso 100 (10% of solvent)                                                                             174                                          (8)  Tetraisopropyl titanate     18                                           ______________________________________                                    

The procedure employed was similar to that in Example 8. The mixture of(5), (6) and (7) was used for thinning. After thinning, (8) was added.The solids were reduced to 17.5% calculated by the addition of 269 gms.of cresylic acid, 39 gms. of Solvesso 100 and 12 gms. of ethylCellosolve. The final viscosity was Z (Gardner-Holdt).

    __________________________________________________________________________    WIRE RESULTS                                                                  __________________________________________________________________________    Speed             40'/min   45'/min.                                          Build             2.9-3.0 mils                                                                            2.9-3.0 mils.                                     Mandrel after snap                                                                              2×  2×                                          Burnout (4 min. at 33 amps)                                                                     10.1 kv   9.3 kv.                                           Reliance burnout (40 amps                                                                       15+min.   15+min.                                           vs. time).                                                                    Cut through       450+-450+° C.                                                                    450+-450° C.                               Heat shock (260° C.)                                                                     40-90-100-100                                                                           70-100-100-100.                                   Freon blister (600 p.s.i. for                                                                   Pass      Pass.                                             72 hours).                                                                    GE repeated scrape                                                                              33 strokes                                                                              24 strokes.                                       Emerson scrape              26.                                               __________________________________________________________________________

                  EXAMPLE 12                                                      ______________________________________                                                                         G.                                           (1)  4,4'-Methylene diphenyl Diisocyanate                                          (0.9 m.)                    225                                               Trimellitic anhydride (0.4 m.)                                                                            77                                                Benzophenone dianhydride (0.2 m.)                                                                         64                                           (2)  Tributyl amine              5                                            (3)  Cresylic acid               1000                                         (4)  Methylene bis(N-phenylglycine ethyl ester)                                    (0.4 m.)                    148                                          (5)  Cresylic acid               134                                          (6)  C.P. Phenol (20% of solvent)                                                                              350                                          (7)  Solvesso 100 (15% of solvent)                                                                             264                                          (8)  Tetraisopropyl titanate     18                                           ______________________________________                                    

The procedure employed was identical with that in Example 11. The solidswere 20%. The final viscosity was Y-1/2 (Gardner-Holdt).

    __________________________________________________________________________    WIRE RESULTS                                                                  __________________________________________________________________________    Speed             40'/min   45'/min.                                          Build             2.8 mils  2.7 mils.                                         Mandrel after snap                                                                              3×  3×                                          Cut through       450+-450+° C                                                                     450+-50+° C.                               Heat shock (260° C.)                                                                     30-80-100-100                                                                           20-80-100-100.                                    Freon blister (600 p.s.i. for 72 hours)                                                         Pass      Pass.                                             GE repeated scrape                                                                              51 strokes                                                                              19 strokes.                                       Emerson scrape              21.                                               Burnout (4 min. at 33 amps)                                                                     10.0 kv.  7.8 kv.                                           __________________________________________________________________________

The major modification of Examples 11 and 12 is that only 0.9 mole of4,4'-methylene diphenyl diisocyanate was employed. The 0.1 equivalentthat was lacking for equivalency was made up with tetraisopropyltitanate. In place of the tetraisopropyl titanate, there can be employedother titanates, e.g. alkyl and aryl titanates such as tetramethyltitanate, tetrabutyl titanate, tetrapropyl titanate, tetrahexyltitanate, tetraphenyl titanate and tetracresyl titanate, as well asother titanates such as titanium glycolate and titaniumtetratriethanolamine.

The major improvements in Examples 11 and 12 over the other examplesare:

(1) they permit faster running speeds on the wire tower,

(2) there is much higher cut through,

(3) there is more consistent mandrel after snap results,

(4) there is more consistent burnout (4 min. at 33 amps),

(5) there is a higher Reliance burnout, and

(6) there is a better Emerson scrape.

It should be noted that one mole of titanate is considered to contain 3equivalents since one of the organic groups is not readily removable.

A number of comparative experiments were run following the teachings ofMerten British Pat. 1,106,915. An attempt to perform Example 37 resultedin the production of a polymer which was insoluble in the recommendedsolvent, dimethyl sulfoxide and diethyl acetamide (weight ratio 1:1).Examples 33 and 34 of Merten were repeated and the products run on thewire with the following results.

    __________________________________________________________________________    WIRE RESULTS-MERTEN EXAMPLE 33                                                __________________________________________________________________________    Speed             35'/min   40'/min.                                          Appearance        Very slightly wavy                                                                      Very slightly wavy                                                  plus.     plus occasional                                                               specks.                                           Mandrel after snap                                                                              3×  2×                                          Cut through       320-315° C.                                                                      282-200° C.                                Heat shock (at 260° C.)                                                                  50-80-100-100                                                                           60-80-100-100.                                    Burnout (4 min. at 33                                                                           5.3 kv.   2.0 kv.                                           amps).                                                                        Freon blister (600 p.s.i. for                                                                   Pass      Pass.                                             72 hours).                                                                    GE scrape         90 strokes                                                                              102 strokes.                                      __________________________________________________________________________    WIRE RESULTS-MERTEN EXAMPLE 34                                                __________________________________________________________________________    Speed             35'/min   40'/min.                                          Appearance        Very slightly wavy,                                                                     Very slightly wavy                                                  occ. specks.                                                                            plus.                                             Mandrel after snap                                                                              2×  2×                                          Cut through                 282-290° C.                                Heat shock (260° C.) 70-90-100-100.                                    Burnout (4 min. at 33       1.9 kv.                                           amps).                                                                        GE scrape                   73 strokes.                                       __________________________________________________________________________

The Gel Permeation Chromatography of Merten's hydantoin and theamide-imide-hydantoin of the present invention were compared. Theamide-imide-hydantoin appears to have a slightly larger molecular size.

What is claimed is:
 1. An amide-imide-hydantoin polymer wherein therecurring hydantoin units are 5 to 95% of the total linkages and theamide groups are 20 to 80% of the total number of the amide and imidegroups, the recurring hydantoin units having the formula: ##STR4##wherein the symbol Ar represents an aromatic hydrocarbon radical or anaromatic hydrocarbon radical carrying a substituent group selected fromthe class consisting of halo, nitro, alkyl, alkoxy, dialkylamino, acyl,carbalkoxy or cyano; the symbol Y represents .Iadd.the residue of thereaction product of trimellitic anhydride and a diisocyanate having theformula OCN-Z-NCO where Z represents .Iaddend.a radical as defined forAr or is an alkylene radical of 4 to 10 carbon atoms, an oxyalkyleneradical of 4 to 10 carbon atoms or a thioalkylene radical of 4 to 10carbon atoms; the symbol R₁ represents hydrogen or an alkyl radical, andwherein the said hydantoin units are formed by reacting (A) a glycinederivative of the formula ##STR5## wherein R₂ is a dialkylamino, alkoxyor aryloxy radical and x is an integer from 2 to 4,with (B) a preformedamide-imide prepolymer having terminal isocyanate groups, saidprepolymer having been prepared by reacting (1) trimellitic anhydride or(2) a mixture of trimellitic anhydride with a dicarboxylic acid orcarboxylic acid dianhydride or tricarboxylic acid with (a) adiisocyanate, or (b) a diisocyanate and up to about 15 equivalentpercent of an organic titanate.
 2. A polymer according to claim 1wherein 20 to 60% of the total linkages are recurring hydantoin units.3. A polymer according to claim 1 wherein 30 to 95% of the totallinkages are recurring hydantoin units.
 4. A polymer according to claim1 wherein 30 to 70% of the total number of amide and imide groups areamide groups.
 5. A polymer according to claim 1 wherein the reactionbetween the trimellitic anhydride and the diisocyanate is carried out inthe absence of solvent and a cresylic solvent of phenol is added as asolvent to the prepolymer thus formed and the glycine derivative isconverted to hydantoin units in the presence of said added solvent andprepolymer.
 6. A polymer according to claim 1 wherein Ar and Y are bothhydrocarbon and the diisocyanate is an aromatic diisocyanate.
 7. Apolymer according to claim 6 prepared from reactants comprising (1).[.0.95.]. .Iadd.0.85 .Iaddend.to 1.05 moles of diisocyanate, (2) 0.05to 0.95 mole of glycine derivative, (3) 0.95 to 0.01 mole of trimelliticanhydride, (4) 0.0 to 0.3 mole of dicarboxylic acid, (5) 0.0 to 0.3 moleof carboxylic dianhydride and (6) 0.0 to 0.05 mole of tricarboxylicacid, (7) 0.0 to 0.06 mole of organic titanate, the total of (2), (3),(4), (5) and (6) being from 1.05 to 0.95 moles.
 8. A polymer accordingto claim 7 wherein the trimellitic anhydride is 100% of the total of(3), (4), (5) and (6).
 9. A polymer according to claim 7 wherein thetrimellitic anhydride is 99.9-.[.9.60.]..Iadd.60.Iaddend.% of the totalmoles of (3), (4), (5) and (6).
 10. A polymer according to claim 7wherein the trimellitic anhydride is 60-100% of the total of (3), (4),(5) and (6).
 11. A polymer according to claim 10 wherein the trimelliticanhydride is present in an amount of 0.05-0.6 mole.
 12. A polymeraccording to claim 10 in which the amount of (6) is
 0. 13. A polymeraccording to claim 10 wherein all R₁ groups are hydrogen.
 14. A polymeraccording to claim 13 wherein the starting glycine derivative ismethylene bis (N-phenylglycine lower alkyl ester).
 15. A polymeraccording to claim 13 wherein Y and Ar are both methylene bis (phenyl).16. A wire enamel composition containing the product of claim 2 in asolvent.
 17. A product according to claim 16 wherein the solvent is acresol solvent.
 18. A product according to claim 17 wherein the solventalso includes an aromatic hydrocarbon.
 19. A wire enamel compositioncontaining the product of claim 1 in a solvent.
 20. An electricalconductor coated with the product of claim
 1. 21. The process ofpreparing the product of claim 1 comprising heating a glycine derivativeof the formula ##STR6## with a preformed amide-imide prepolymer havingterminal isocyanate groups.
 22. A process according to claim 21 whereinthere is included a small amount of an organic titanate as a reactant.23. A product according to claim 1 wherein the polymer contains at least30% of the total linkages as recurring hydantoin units and the polymeris modified by containing titanate linkages.
 24. A process according toclaim 21, including the steps of forming said preformed amide-imideprepolymer by (a) reacting the trimellitic anhydride and diisocyanate inthe absence of a solvent, (b) adding a cresylic solvent or phenol as asolvent to the prepolymer thus formed and converting the glycinederivative to hydantoin in the presence of said added solvent andprepolymer.
 25. A polymer according to claim 10 wherein the trimelliticanhydride is present in an amount of 0.4-0.5 mole.